Fix crash on Windows (#2021)

The rusttype backend did not properly support manually specifying font
styles, but instead chose to panic when they are specified.

The rusttype implementation now provides a proper implementation for
handling `bold`, `italic` and `regular` font styles.

This fixes #2020.

1 files changed, 7 insertions, 1 deletions

diff --git a/font/src/rusttype/mod.rs b/font/src/rusttype/mod.rs
index add23605..e8e0bd2c 100644
--- a/font/src/rusttype/mod.rs
+++ b/font/src/rusttype/mod.rs
@@ -61,7 +61,13 @@ impl crate::Rasterize for RustTypeRasterizer {
             .monospace();
 
         let fp = match desc.style {
-            Style::Specific(_) => unimplemented!(""),
+            Style::Specific(ref style) => {
+                match style.to_lowercase().as_str() {
+                    "italic" => fp.italic(),
+                    "bold" => fp.bold(),
+                    _ => fp,
+                }
+            },
             Style::Description { slant, weight } => {
                 let fp = match slant {
                     Slant::Normal => fp,